The Festungsfront Oder-Warthe-Bogen (Fortified Front Oder-Warthe-Bogen), also called the Festung im Oder-Warthe-Bogen or Ostwall (East Wall), and in Polish the Międzyrzecki Rejon Umocniony, MRU (Międzyrzecz Fortification Region), was a fortified military

defence line Defense or defence may refer to: Tactical, martial, and political acts or groups * Defense (military), forces primarily intended for warfare * Civil defense, the organizing of civilians to deal with emergencies or enemy attacks * Defense industr ...

Nazi Germany Nazi Germany, officially known as the German Reich and later the Greater German Reich, was the German Reich, German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a Totalit ...

between the

Oder The Oder ( ; Czech and ) is a river in Central Europe. It is Poland's second-longest river and third-longest within its borders after the Vistula and its largest tributary the Warta. The Oder rises in the Czech Republic and flows through wes ...

and

Warta The river Warta ( , ; ; ) rises in central Poland and meanders greatly through the Polish Plain in a north-westerly direction to flow into the Oder at Kostrzyn nad Odrą on Poland's border with Germany. About long, it the second-longest riv ...

rivers, near

Międzyrzecz Międzyrzecz (; , , ) is a town in western Poland, on the Obra (river), Obra and Paklica river, with 17,667 inhabitants (2020). The capital of Gmina Międzyrzecz and Międzyrzecz County. Since the Local Government Reorganization Act of 1998, it ha ...

. The part around Międzyrzecz (Meseritz) has been colloquially referred to as the Regenwurmlager (). Built in 1934–44, it was the most technologically advanced fortification system of

, and remains one of the largest systems of this type in the world today. It consists of around 100 concrete defence structures partially interconnected by a network of tunnels. Some of the forts and tunnels are available for visiting. The most interesting part is the central section, which begins in the south with the so-called Boryszyn Loop near the village of Boryszyn (Burschen) and extends about 12 km to the north. Another interesting part of MRU is located in Pniewo (Fischerhaus) in the Międzyrzecz District. In the central section the bunkers are interconnected with a system of tunnels, long and up to deep. In the underground system there are also railway stations, workshops, engine rooms and barracks. It is also among the top 10 largest hibernation sites for

bats Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

in Europe according to the data of the EUROBATS Agreement. The numbers of hibernating bats exceeds 39 000 individuals in some years. 12 species have been found hibernating there and one more (the

northern bat The northern bat (''Eptesicus nilssonii'') is the most abundant species of bat in northern Eurasia occurring from France to Hokkaidō and south to Kazakhstan. Description The northern bat is dark brown or black with some gold touched at the tip ...

) roosts in cooler stand alone bunkers not connected with the underground system.Kokurewicz, T., Apoznański, G., Gyselings, R., Kirkpatrick, L., De Bruyn, L., Haddow, J., ... & Rachwald, A. (2019)
45 years of bat study and conservation in Nietoperek bat reserve (Western Poland)
Nyctalus, 19(3), 252-269.

History

The design works of the fortified defence line started in Germany in 1932. The first stage, until 1935, included constructing of water obstacles and 12 light

bunker A bunker is a defensive military fortification designed to protect people and valued materials from falling bombs, artillery, or other attacks. Bunkers are almost always underground, in contrast to blockhouses which are mostly above ground. T ...

Adolf Hitler Adolf Hitler (20 April 1889 – 30 April 1945) was an Austrian-born German politician who was the dictator of Nazi Germany from 1933 until Death of Adolf Hitler, his suicide in 1945. Adolf Hitler's rise to power, He rose to power as the lea ...

visited the construction site in the end of 1935. The end of works was scheduled for 1951. The Soviet army reached the defence line in the course of the Vistula–Oder Offensive in January 1945, before the Germans could deploy troops; the line was broken in three days.

References

External links

The Fortified Front of Odra-Warta Rivers, Boryszyn Loop

Information about the Boryszyn Loop

Information and Pictures

Short inspection video 2019
Military installations of the Wehrmacht World War II defensive lines Forts in Poland Bunkers in Germany Tunnel warfare Bat conservation World War II sites in Poland History of Lubusz Voivodeship Urban warfare in World War II Buildings and structures in Lubusz Voivodeship {{Germany-WWII-stub